binding: Lets Dictionary::getPropertyNames, etc. rethrow an exception.

third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 134 matching lines @@
 const char kGoogLeakyBucket[] = "googLeakyBucket";
 const char kPowerLineFrequency[] = "googPowerLineFrequency";
 // Names used for testing.
 const char kTestConstraint1[] = "valid_and_supported_1";
 const char kTestConstraint2[] = "valid_and_supported_2";
 
 static bool parseMandatoryConstraintsDictionary(
     const Dictionary& mandatoryConstraintsDictionary,
     Vector<NameValueStringConstraint>& mandatory) {
   HashMap<String, String> mandatoryConstraintsHashMap;
+  TrackExceptionState exceptionState;

[haraken, 2016/11/24 07:22:31]

We should avoid using TrackExceptionState in production code. Shall we add a
TODO to fix it?

[Yuki, 2016/11/24 10:19:33]

MediaConstraintsImpl looks a little bit different.  See the call sites of this
function and APIs in MediaConstraintsImpl.

MediaContraintsImpl is intentionally using MediaErrorState, which looks similar
to ExceptionState but different.
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/modules/medias...

MediaContraintsImpl was designed to use MediaErrorState to delay an error
handling.  If parseMandatoryConstraintsDictionary() returned false, then the
call sites create an appropriate MediaErrorState.  So we don't need to have an
ExceptionState here (at least with this approach).

Thus, it seems okay for me to just use TrackExceptionState.

[haraken, 2016/11/24 12:39:13]

Okay. However, in long term I think we should replace MediaErrorState with
ExceptionState and remove TrackExceptionState though.

[Yuki, 2016/11/25 08:31:04]

Acknowledged.

   bool ok = mandatoryConstraintsDictionary.getOwnPropertiesAsStringHashMap(
-      mandatoryConstraintsHashMap);
+      mandatoryConstraintsHashMap, exceptionState);
   if (!ok)
     return false;
 
   for (const auto& iter : mandatoryConstraintsHashMap)
     mandatory.append(NameValueStringConstraint(iter.key, iter.value));
   return true;
 }
 
 static bool parseOptionalConstraintsVectorElement(
     const Dictionary& constraint,
     Vector<NameValueStringConstraint>& optionalConstraintsVector) {
   Vector<String> localNames;
-  bool ok = constraint.getPropertyNames(localNames);
+  TrackExceptionState exceptionState;
+  bool ok = constraint.getPropertyNames(localNames, exceptionState);
   if (!ok)
     return false;
   if (localNames.size() != 1)
     return false;
   const String& key = localNames[0];
   String value;
   ok = DictionaryHelper::get(constraint, key, value);
   if (!ok)
     return false;
   optionalConstraintsVector.append(NameValueStringConstraint(key, value));
   return true;
 }
 
 // Old style parser. Deprecated.
 static bool parse(const Dictionary& constraintsDictionary,
                   Vector<NameValueStringConstraint>& optional,
                   Vector<NameValueStringConstraint>& mandatory) {
   if (constraintsDictionary.isUndefinedOrNull())
     return true;
 
   Vector<String> names;
-  bool ok = constraintsDictionary.getPropertyNames(names);
+  TrackExceptionState exceptionState;
+  bool ok = constraintsDictionary.getPropertyNames(names, exceptionState);
   if (!ok)
     return false;
 
   String mandatoryName("mandatory");
   String optionalName("optional");
 
   for (Vector<String>::iterator it = names.begin(); it != names.end(); ++it) {
     if (*it != mandatoryName && *it != optionalName)
       return false;
   }
@@ skipping 598 matching lines @@
     MediaTrackConstraintSet element;
     convertConstraintSet(it, element);
     advancedVector.append(element);
   }
   if (!advancedVector.isEmpty())
     output.setAdvanced(advancedVector);
 }
 
 }  // namespace MediaConstraintsImpl
 }  // namespace blink